A Moving Window Principal Components Analysis Based Anomaly Detection and Mitigation Approach in SDN Network

( Mingxin Wang ),( Huachun Zhou ),( Jia Chen ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.8

Network anomaly detection in Software Defined Networking, especially the detection of DDoS attack, has been given great attention in recent years. It is convenient to build the Traffic Matrix from a global view in SDN. However, the monitoring and management of high-volume feature-rich traffic in large networks brings significant challenges. In this paper, we propose a moving window Principal Components Analysis based anomaly detection and mitigation approach to map data onto a low-dimensional subspace and keep monitoring the network state in real-time. Once the anomaly is detected, the controller will install the defense flow table rules onto the corresponding data plane switches to mitigate the attack. Furthermore, we evaluate our approach with experiments. The Receiver Operating Characteristic curves show that our approach performs well in both detection probability and false alarm probability compared with the entropy-based approach. In addition, the mitigation effect is impressive that our approach can prevent most of the attacking traffic. At last, we evaluate the overhead of the system, including the detection delay and utilization of CPU, which is not excessive. Our anomaly detection approach is lightweight and effective.

Study on treatment of acid mine drainage by nano zero-valent iron synergistic with SRB immobilized particles

Xianjun Wang,Junzhen Di,Bing Liang,Yu Yang,Yanrong Dong,Mingxin Wang 대한환경공학회 2021 Environmental Engineering Research Vol.26 No.5

In view of the serious pollution and high cost of treatment of acid mine drainage (AMD) in coal mine, the polyving akohol (PVA) and boric acid embedding cross-linking method was used to prepare the immobilized particles for treatment of AMD with sulfate-reducing bacteria (SRB) and nano zero-valent iron (nano-Fe⁰) as the main body. In order to explore the specification and dosage of each matrix component of immobilized particle, a series of single factor tests and orthogonal tests were carried out to determine the optimal ratio of each matrix component. The results shows that when the SRB quality additive percentage was 30%, the nano-Fe0 dosage was 4%, the corn cob particle size was 60 mesh and the dosage was 3%, the SO₄<SUP>2-</SUP>, Cr<SUP>6+</SUP> and Cr<SUP>3+</SUP> removal rates were 82.99%, 99.78% and 38.78%, respectively, the TFe and COD release rates were 4.26 ㎎·L<SUP>-1</SUP> and 1,033.4 ㎎·L<SUP>-1</SUP>, respectively, and the pH value was 8.04, and the treatment effect was the best.

Observation and Mechanism of Photo-isomerisation Induced Rapid Photo-degradation of Optical Nonlinearity in Guest-host Type Poled Polymer

Mingxin Ye,Lei Xu,Jieyun Yan,Liying Liu,Liyong Ji,Wencheng Wang 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.32

Photo-degradation of electric eld poled alpha0-cyano-40-nitro-4-N,N-dimethylaminostilbene (CNDS) doped polymer was investigated by second-harmonic generation (SHG), UV-Vis absorption and FTIR. We found that the addition of a cyano group makes CNDS much more easily photoisomerized, and thus destroys the molecular ordering in poled chromophore doped polymers. A comparison experiment revealed that the photo-isomerization of CNDS is even easier than that of a modal system of azobenzene, which shows that CNDS has potential applications, such as in optical switches.

An engineering-based assessment methodology on the loss of residential buildings under wind hazard

Mingxin Li,Guoxin Wang 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.1

The loss prediction and assessment during extreme events such as wind hazards is always crucial for the group low-rise residential buildings. This paper analyses the effect of variation in building density on wind-induced loss for low-rise buildings and proposes a loss assessment method consequently. It is based on the damage matrices of the building envelope structures and the main load-bearing structure, which includes the influence factors such as structure type, preservation degree, building density, and interaction between different envelope components. Accordingly, based on field investigation and engineering experience, this study establishes a relevant building direct economic loss assessment model. Finally, the authors develop the Typhoon Disaster Management System to apply this loss assessment methodology to practice.

Video-based Height Measurements of Multiple Moving Objects

( Mingxin Jiang ),( Hongyu Wang ),( Tianshuang Qiu ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.9

This paper presents a novel video metrology approach based on robust tracking. From videos acquired by an uncalibrated stationary camera, the foreground likelihood map is obtained by using the Codebook background modeling algorithm, and the multiple moving objects are tracked by a combined tracking algorithm. Then, we compute vanishing line of the ground plane and the vertical vanishing point of the scene, and extract the head feature points and the feet feature points in each frame of video sequences. Finally, we apply a single view mensuration algorithm to each of the frames to obtain height measurements and fuse the multi-frame measurements using RANSAC algorithm. Compared with other popular methods, our proposed algorithm does not require calibrating the camera, and can track the multiple moving objects when occlusion occurs. Therefore, it reduces the complexity of calculation and improves the accuracy of measurement simultaneously. The experimental results demonstrate that our method is effective and robust to occlusion.

The Orphan of China in Voltaire’s Eyes: Analysis on Elements of Chinese Cultures in Ji Junxiang’s The Orphan of Zhao

Jindi Jiang,Mingxin Wang 강원대학교 인문과학연구소 2019 Journal of Humanities Therapy Vol.10 No.1

Elements of Chinese Cultures, those Confucian one particularly, help Voltaire unveil how the foreign country looks like and meanwhile serve as a crucial means of him in building its vast empire of literature. Through The Orphan of China, are written poetic drama based on Yuan verse The Orphan of Zhao which written by Ji Junxiang. Voltaire had Chinese Cultures and morality of Confucianism greatly propagated. In this drama, the Song Dynasty collapsed, but its conqueror Genghis Khanwa sultimately conquered by the Song cultures and virtues. Voltaire acclaimed the moral and spiritual excellence contained in The Orphan of Zhao and on the other hand satirized the spiritual deprivation and moral for forfeiture then in France, both of which accorded with his acceptance of The Orphan of Zhao. Voltaire presented The Orphan of China on the stage to dramatize elements of Chinese Cultures, and that was not a choice of art but rather that of culture, namely the Chinese moral culture.

Simulation Studies on the Hemodynamics of a Centrifugal Ventricular Assist pump

Haiquan Feng,Dong Wang,Kun Wang,Mingxin Zhu 한국유체기계학회 2019 International journal of fluid machinery and syste Vol.12 No.3

The present study was aimed to reveal the possible interactions between the left ventricular assist pump and the blood. The study presented in here adopted the computational fluid dynamics approach to analyze the effects of variations in blade height, rotation speed, and suspension height on the dynamic performance of the left ventricular assist pump. In addition, the 3D printing technology was tested as a reliable of manufacture of the assembly parts the left ventricular assist pump. The study was designed and conducted only after system debugging was accomplished. The computer-aided simulation results showed that the blade height, rotation speed and suspension height had varied functional on the dynamic performance of the device. Comparison of the influence degree of each factor to that of the blood indicated that rotation speed has the largest impact, followed by the blade height and finally the suspension height. At the same time, the experimental results proved that the design principle was rational and if prepared the left ventricular assist pump could operate successfully. The computer-aided simulation and experiment also reproduced the possible effects of the various factors on the blood and provided a theoretical reference for the design of the centrifugal ventricular assist pump.

Adaptive robust control of active magnetic bearings rigid rotor systems

Yuhao Xu,Xiaoyuan Wang,Mingxin Liu,Na Li,Tian Yu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.6

Aiming at the problems of diffi cult decoupling, complex controller models, and poor disturbance rejection capability caused by the inherent nonlinear and strong coupling characteristics of the active magnetic bearing (AMB), an adaptive H-infinity robust control (AHRC) method is proposed in the AMBs-rigid rotor system. The proposed method combines the active disturbance rejection control (ADRC) with the robust control to achieve stable operation of the AMBs-rigid rotor system under high-speed conditions. First, a four-degree-of-freedom (4-DOF) AMBs-rigid rotor model was established and transformed into a one-degree-of-freedom (1-DOF) model for the design of the robust controller, which weakens the coupling effect between each of the degrees of freedom (DOF). Then the multi-objective non-dominated sorting genetic algorithm II (NSGA-II) was used to fi nd the relative optimal weighting function value of the H-infinite robust control (HRC), which solved the difficulties in the design of the robust controller for known controlled system models. In addition, by combining the optimized H-infi nity robust controller with the original error feedback control rate in the ADRC, the proposed AHRC retains the strong robustness of the HRC and the decoupling capability of the ADRC, which improves the tracking performance and anti-disturbance performance of the controlled system. Simulation and experimental results verify the effectiveness of the proposed method.

Collision-Free Adaptive Control for UAV Formation with Input Saturation and Communication Delays

Jianhui Lu,Fan Luo,Zhong Zheng,Mingxin Hou,Lin Wang 한국항공우주학회 2022 International Journal of Aeronautical and Space Sc Vol.23 No.3

This paper addresses the collision-free adaptive formation control problem for multiple unmanned aerial vehicles subject to input saturation and communication delays. First, a novel collision-free adaptive saturated control scheme is proposed using potential function and anti-windup compensator approaches. It shows that the velocity consensus and collision avoidance are realized when the directed communication topology is strongly connected. Second, the collision-free adaptive saturated control algorithm is proposed considering communication delays and collision avoidance, and it enables the asymptotic stability of the closed-loop system when the time-varying communication delays are decreasing to zero eventually. Finally, numerical simulations demonstrate that the proposed control approaches are effective, while the objectives of collision avoidance and velocity consensus are fulfilled.

Trisodium citrate-assisted synthesis of BiOBr nanostructure catalyst for efficient activity under visible light

Weiming Zhou,Yifan Jiang,Shichang Sun,Mingxin Zhang,Ibrahim Lawan,Gerard Franklyn Fernando,Liwei Wang,Zhanhui Yuan 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

A simple one step wet-chemical method assisted by trisodium citrate was employed in the synthesis of BiOBr applied as a photocatalyst. Photocatalytic activity of the BiOBr was investigated for the degradation of Rhodamine B (RhB) dye under visible light irradiation (>420 nm). The results indicated that trisodium citrate is more favorable to the formation of hierarchical architectures and reduces the particle size of BiOBr photocatalyst. BiOBr with hierarchical architectures exhibiting significantly higher catalytic activity than that with ordinary nanostructure. The significant improvement could be attributed to the high specific surface area (24.14m2·g1), average pore sizes (34.09 nm) and average pore volume (0.24 cm3·g1).